Tow-type two-wheeled vibratory trench roller apparatus



Sheet NNN@ HH i l l V TOW- TYPE TWO- Feb. 18, 1969 Filed Sept.. l5, 1966 Feb. 18, 1969 R, D, MaCDONALD 3,427,940

WHEELED VIBRATORY TRENCH ROLLER APPARATUS TOW-TYPE TWO- Sheet of4 Filed Sept.

IIIII.'

ARATUS Feb. 18, 1969 R, D MacDONALD TOW-TYPE TWO-WHEELED VIBRATORY TRENCH ROLLER APP 15, 196e Sheet Filed Sept.

f4 ff Feb. 18, 1969 R, D. MaoDoNALD 3,427,940

WHEELED VIBRATORY TRENCH ROLLER APPARATUS Tow-TYPE Two- Filed Sept.

United States Patent O1 3,427,940 Patented Feb. 18, 1969 lice ABS'l/'RACT 0F THE DISCLOSURE A two-wheeled tow-type vibratory trench roller having vibration isolating means which isolates the main frame from vibratory impulses imparted to the compacting roller by a vibrator assembly, said assembly being easily removable from the compacting roller for maintenance and repair.

This invention relates generally to compacting devices and particularly to a two-wheeled tow-type vibratory trench roller.

Accordingly, a primary object of the invention is to provide a tow-type trench roller especially adapted for narrow shoulder trenching work.

Another object is to provide a tow-type trench roller having only two rolling support points, one of which is a Vcompacting roller.

Yet another object is to provide a trench roller of the type described above having a vibratory mechanism associated with the compacting roller.

Yet another object is to provide a trench roller of the type described above in which the direction of movement of the roller may be quickly and easily reversed by merely changing a tow bar from fore to aft positions.

Yet a further object is to provide a tow-type trench roller as described in the preceding paragraph which includes a tow bar assembly so arranged as to always exert a movement impelling force on the compacting roller through the center of gravity of the apparatus irrespective of the positions of the towing vehicle and the trench roller to thereby control or eliminate any undesired towin or tow-out tendency of the trench roller, or unbalanced force coupling.

Yet a further object is to provide a trench roller as described in the immediately preceding paragraph in which only one fastener is needed to assemble the tow bar to the remainder of the apparatus.

Another object is to provide a tow-type trench roller having a cartridge type vibratory mechanism which is easily assembled and disassembled to the compacting roller whereby repair and replacement is materially simplilied.

A further object is to provide a vibratory trench roller having a straight-through drive from the drive motor carried by the roller frame to the Ivibratory assembly associated with the compacting roller wherein the drive motor shaft is substantially aligned with the rotational axis of the vibrator, thereby eliminating V-belts, chains, or other conventional drive systems which are much more susceptible to wear.

A further object is to provide a two-wheel, tow-type vibratory trench roller in which the relative positions of the vibratory drive motor and the compacting roller is maintained level and iixed with respect to one another throughout the entire range of compaction depth.

Yet a further object is to provide a two-wheel tow-type vibratory trench roller as described above further characterized in that the compaction depth is varied by a single cylinder and piston arrangement.

Other objects and features of the invention will become apparent from a reading of the following description thereof.

The invention is illustrated more or less diagrammatically in the accompanying iigures wherein:

FIGURE 1 is a side elevation with parts shown in dotted lines of the trench roller of this invention in the maximum compaction depth condition;

FIGUR'E 2 is a top plan view in a road travel position;

FIGURE 3 is a View taken substantially along the line 3-3 of FIGURE '2, with the trench rolle-r in the position of FIGURE 1;

FlIGURE 4 is a partial sectional view with parts broken away for clarity of the compacting roller and vibratory power mechanism drawn to an enlarged scale as contrasted to FIGURE 2; and

FIGURE 5 is a left side View illustrating the wheel leveling assembly in a road travel position.

Like parts will be referred to by like reference numerals from figure to ligure throughout the following description.

In the embodiment chosen for illustration the invention is shown as it would be used in the preparation of a trench alongside an existing road. While it is contemplated that this will be the primary eld of application of the invention it will be readily understood by those skilled in the art that the invention is not so limited. It may be used whenever a compacted surface must be prepared and a suitable moving means, such as a truck or trailer, is available to propel the assembly.

The' trench roller of this invention is indicated generally at 10 in FIGURIE l. The roller includes frame means, indicated generally at 11, a leveling wheel assembly carried by the frame means, indicated generally at 12, and a compacting roller indicated generally at 13. The compacting roller includes a vibratory mechanism indicated generally at 14 and means for connecting the frame means, and thereby the compacting roller, to suitable structure for moving the assembly. In this instance, the connecting means is a tow bar indicated generally at 15. For purposes of illustration a small truck or tractor is indicated at 16, the tow vehicle having a towing bracket 17 and means 18 for connecting the Itow bar 15 to the towing vehicle 16.

As best seen in FIGURES 1 and 3 the towing vehicle 16 moves over reference surface 20 while the compacting roller 13 rolls over loose earth 21 to provide a at, compacted surface 22. It will thus be observed that the trench roller has only two rolling support points, one of which is the compacting roller 13.

Frame means 11 consists essentially of a main frame 25 and a sub or auxiliary frame 26 shown best in FIG: URES 2 and 4. The main frame consists of a pair of generally transversely positioned` structural members 27, 28, which are welded at their outer ends to a box frame structure 29 and, at their inner ends to a strut 30. A platform 31 spans the distance between members 27 and 28 to form a support base for a power plant which will be described in detail hereinafter.

Box frame 29 includes inner and outer longitudinal members 32a, 32b, and four cross members 33, 34, 35 and 36. lEach of members 33-36 is welded at one end to an adjacent one of the two longitudinal members 32a, 32b, and terminates at its other end in a ilange, the four anges being indicated at 37, 38, 39 and 40, respectively. The flanges are secured to one another by any suitable means such as bolts 41 shown best in FIGURE 3.

The auxiliary frame 26 consists of twol members 42, 43 which are connected to the inner surfaces of box frame members 32a, 32h by pairs of rubber vibration isolating members 44, 45. These members may be composed of rubber, or in the alternative, of any suitable material having the characteristics, with respect to exure and compressi'bility, of rubber. As best seen in FIGURE 4 a plurality of `fasteners 46, 47 extend, respectively, from the box frame 29 to the vibration isolators. A pair of annular bearing retainers are indicated at 48, 49, said retainers being welded or other-wise suitably secured to auxiliary frame members 42 and 43 respectively.

The compacting roller 13 includes a shell 50 of any suitable width and a pair of side walls 51, 52. The side walls are apertured to receive rings 53, 54 which in turn receive a vibrator housing 55 as shown best in FIG- URE 4.

The drum 50 including its side walls 51, 52, rings 53, 54 and vibrator housing 55 are rotatably supported from the auxiliary frame 26 by the following structure.

A pair of vibrator assembly cartridge end caps are indicated at 56 and 57. lEach end cap includes a barrel portion, indicated at 56a and `57a being received within rings 53 and 54 respectively. A plurality of suitable fasteners 58 which pass through anges 56b and `57b connect end caps 56, 57 to rings 53 and 54 respectively. Each end cap 56, 57 also includes a shank portion 56C, 57C respectively, the shank portions having an enlarged internal bore. Each of the shank portions is machined as at 56d and 57d to form a seat for the inner race of an annular roller bearing assembly, said assemblies being indicated at V56e and 57e. The outer race of each of bearings 56e and 57e is received in complementary seat found in bearing retainers 49, 48 respectively. If desired, end caps 56 and 57 may be identical and interchangeable. A dust cover 59 which is fastened to bearing retainer 49 has an inwardly extending projection 59a which maintains the bearing '56e seated in retainer 49. A similar cover member 60 iwhich is fastened to bearing retainer 48 has an inwardly extending projection `60a which maintains bearing 57e seated in retainer 48. Additional bearing retaining means is indicated at 61. It is thus apparent that the compactin-g roller 13 is rotatably carried by the sub-frame assembly 26 and, by virtue of the rubber vibration isolators 44, 45, the main frame 25.

Means Ifor imparting vibratory motion to the compacting roller 13 is indicated generally at 14. The vibratory mechanism includes a gasoline engine mounted on en'gine platform 31 on the main frame. A speed reducer is indicated at 71 and an engine drive shaft at 72.

Flexible means for coupling the engine drive sha-ft 72 to the eccentric 62 which imparts vibratory impulses to compacting roller i13 are illustrated best in FIGURES 2 and 4. The exible coupling means includes a splined shaft 73 which is connected by a first universal joint 74 to drive shaft 72 and by a second universal joint 75 to the input end 76 of the vibrator shaft 77. Universal joint 75 includes a first portion 75a which is slidably received on a splined shaft 73, and a second portion 75b which is connected, as by a conventional key arrangement, to the power input end 76 of shaft 77. At least one, and preferably both, of the universal connections are so formed as to be telescopingly received on the connecting shaft 73.

kPower supplied to the input end 76 causes rotation of eccentric 62 as shown best in FIGURE 4. It will be noted that shaft 77 includes a reduced diameter portion 78 which has an external diameter smaller than the internal -diameter in shank portion 57c of end cap 57 so that the vibrator shaft 77 may rotate freely 'with respect thereto. The cartridge cap 57 rotates with the compactor drum 13, and at a much slower rate than shaft 77.

The eccentric 62 is supported on a pair of bearings 79, 80 which are seated within barrel portions 56a and 57a respectively, of the end caps 56 and 57.

The leveling wheel assembly 12 includes a conventional rubber tire 83 which rotates freely about shaft 84, the shaft being carried by a yoke which includes arms 85 and 86 which are welded to a collar 87. Collar 87 is integrally secured to a shaft 88 which is journaled at its outer end, in a bracket y89 carried by the outer end of frame member 28, and, at its inner end in strut 30. A

bell crank 90, the outline of which is shown best in FIG- URE 5, includes wheel arms 85, 86 and an actuator arm 92, the junction of the arms being rigidly secured to shaft 88. A hydraulic cylinder and piston assembly is indicated at 94, the assembly including a cylinder which is pivotally connected as at 96 to the main frame and a piston rod 97 which is -pivotally connected as at 98 to the short arm 92 of the bell crank. By extending and retracting the piston rod 97 rubber tire 83 will be swung along the arc 99 shown in FIGURE 5 from the solid line road travel position of FIGURE 5 to any location up to and including the dotted line position of FIGURE 5.

Tow bar :15 may take any suitable form. In this instance a box frame construction, shown best in FIGURE 3, has been chosen, the box frame terminating at its innermost end at a curved ange 100 which has a plurality of connecting apertures 101, 1102 and 103, formed therein. A generally complementarily contoured seating plate 104 is located on the main frame. As can best be seen in FIGURE 2 the radius of curvature of plate or flange 100 is greater than the radius of curvature of the seating plate 104. Any suitable connector, such as bolt 106 which is received in housing `107, secures tow bar 15 to the frame in any one of the three position holes illustrated in FIGURE 2. In the illustrated FIGURE 2 position there Iwill be in effect a three point connection between the tow bar and the frame since contact will be made between plates 100 and 104 at a point on either side of connecting bolt 106. In any event, irrespective of which of the connection positions are selected, at least a two 'point connection will be made to the frame means.

The center of gravity of the assembly is indicated generally at 108 and it will be noted that the pulling or towing force furnished by the towing vehicle will always pass through the center of gravity.

Frame member 27 includes a curved seating plate l110, similar to seating plate 104, and bolt receiving structure 111, similar to housing 107, so that the direction of travel of the trench roller can be reversed by simply disconnecting tow bar 15 from the illustrated FIGURE 2 position and reassembling it to the phantom line position of FIGURE 2.

The use and operation of the invention are as follows:

The trench roller of this application is particularly well adapted for narrow shoulder trenching work of the type required in the widening of highways. Preferably, the compacting roller 13 has a Width which is either equal to or an even fraction or multiple of the width by which the highway must be widened. If, for example, a 20 foot highway is to be widened to a total of 24 feet to conform with the present United States Government standards, the roller is preferably approximately 24 inches in width.

In operation, tow bar 15 is connected to the frame means 11 by bolt 106 which urges the plate 100 into seating engagement with seat 104. Since the radius of curvature of the plate member 100 is greater than the radius of curvature of the concave surface formed in seating member 104, at least a two-point, and usually a three-point contact, will be formed by the use of the single fastener 106. The position of the tow bar with respect to the frame 11 may be varied to allow for available clearance and the width of the towing vehicle. If a towing vehicle is employed in which the tow bar connecting means 17 carried by the vehicle is close to the edge of pavement 9, the tow *bar 15 may be assembled to the frame in the illustrated solid line position of FIG- URE 2. If the towing vehicle 16 has a tow bar connection which is located some distance inwardly from the edge of the vehicle as, for example, might be the case where a conventional highway truck is employed, tow bar 15 may be assembled in the dotted line position of FIGURE 2. In either event the direction of pull passes through the center of gravity 108, thereby eliminating any unbalanced force coupled on the assembly which would tend to cause the compacting roller to toe inwardly or outwardly an undesired amount. It might, however, be desirable for the compacting roller to have a slight inward toeing tendency so that the compacting roller `will not Wander away from the vertical edge of the pavement 9. This can be easily accomplished by suitable redesign of the location of the connecting means, all of which will at once be apparent to one skilled in the art.

The compaction depth is regulated by hydraulic piston and cylinder assembly 94 which may be controlled by any suitable means not shown.

If the maximum compaction depth is desired, as illustrated in FIGURE 1, the piston and cylinder assembly 94 is operated to extend the piston rod 97 thereby swinging tire 83 counterclockwise, as viewed in FIGURE 5, up to the AFIGURE 1 position. By suitable regulation of the piston and cylinder assembly 94 the tire 83 can be placed in any desired position between the positions of FIGURES 5 and 1. In FIGURE 5 piston rod 97 has been retracted to its fullest extent and tire 83 has been lowered with respect to the frame due to the clockwise movement of bell crank 90 about the axis of shaft 88. In this condition the trench roller may be towed along a road or other surface from job site to job site.

Whether the trench roller is operating, or merely moving from job site to job site, only two rolling support points have been provided. In this connection it will be understood that the leveling wheel assembly may include one or more tires, the number chosen being dependent upon other factors such as total weight, weight distribution, etc. Irrespective of whether one or more than one tire is employed it is considered that the leveling wheel lassembly provides only a single point of rolling support.

The compacting roller 13 is vibrated by the vibrator assembly illustrated best in FIGURES 2 and 4. In this instance the vibrator assembly includes an eccentric 62 which is journaled in bearings 79 and 80, the outer races of these bearings being carried by the barrel portions 56a and 57a of end caps 56 and 57 which are fastened to the drum 50 of roller 13.

The eccentric is driven by any suitable power source, such as gasoline engine 70 located on the main frame 11. Power from the engine is transmitted to the eccentric by a pair of universal connectors 74, 75 which connect, respectively, the engine drive shaft to coupling shaft 73, and coupling shaft 73 to the input end 76 of the eccentric shaft. That portion of at least one, and preferably both, of the universal joints which are secured to the coupling shaft 73 are splined to the shaft to accommodate the slight increases and decreases in shaft length which occur as the vibrating mechanism operates. The splined connections further function to help isolate the gasoline engine, and the frame means, from the vibrations induced by the eccentric 62.

The primary vibration isolating means are shown best in FIGURES 2 and 4. The roller 13 is directly supported by drum bearings 56e and 57e which are carried by sub frame members 42 and 43. The sub frame 26 is connected to the box frame structure 29, which is connected to main frame 25, by the elastomeric isolators -44 and 4S. Preferably the isolators are composed of rubber butin any event they should have the characteristics with respect to flexure and compressibility of rubber. Their primary function is todampen vibrations imposed on the compacting roller by the eccentric 62 so that the vibrations are not transmitted to the balance of the machine.

A unique feature of the trench roller is the easy replacability of the vibrating mechanism. As best illustrated in FIGURES 2 and 4 easy access may be had to the vibrator cartridge assembly by merely loosening fasteners 41 to thereby separate the two halves of box frame 29. Once the box frame 29 is opened and universal joint 75 disconnected, the Vibrator cartridge can be removed by loosening the bolts 58 which secure end cap 56 to the side wall 52 of the roller. By keeping a spare vibrator cartridge as- 75 sembly in stock, the user can quickly and easily replace a worn or defective vibrator with a minimum of down time. Although a preferred embodiment of the invention has been illustrated and described in detail, it will at once be apparent that further modifications may be made within the spirit and scope of the invention. Accordingly, it is intended that the scope of the invention be limited not by the scope of the foregoing exemplary description but solely by the scope of the hereinafter appended claims.

I claim:

1. In combination in a two-wheeled tow-type vibratory trench roller,

frame means,

a compacting roller rotatably connected to the frame means,

a leveling wheel assembly connected to the frame means, said leveling wheel assembly including means for maintaining the height of the frame means with respect to a reference surface whereby said frame means will be level regardless of the difference in the height of the reference surface and a surface to be compacted by said compacting roller, vibration generating means mounted on the compacting roller and effective to impart vibratory impulses thereto, and

means fastened to said frame means for connecting the frame means, and thereby the compacting roller, to means for moving the trench roller along the reference surface,

said trench roller thereby having only two rolling support points.

2. In combination in a trench roller,

frame means,

a compacting roller rotatably connected to the frame means,

a leveling wheel assembly connected to the frame means,

said leveling wheel assembly including means for maintaining the height of the .frame means with respect to a reference surface whereby said frame means will be level regardless of the difference in the height of the reference surface and a surface to be compacted by said compacting roller,

means fastened to said frame means for connecting the frame means, and thereby the compacting roller, to means for movin-g the trench roller along the reference surface,

said trench roller thereby having only two rolling support points, and

vibration generating means mounted on the compacting roller and effective to impart vibratory impulses thereto, said vibration generating means including a vibrator mounted on the roller,

vibrator power means attached and flexible shaft means coupling the power means to the vibrator for isolating the power means from the vibratory impulses generated by the vibrator.

3. The trench roller of claim 2 further characterized iirstly, in that the power means includes a drive shaft,

and

secondly, in that the flexible shaft means couples the vibrator to the drive shaft and is nominally aligned with the axis of the drive shaft and the compacting roller in all relative positions of the compacting roller and frame means with respect to the reference surface.

4. The trench roller of claim 3 further characterized in that the iiexible shaft means coupling the power means to the vibrator includes a power shaft universally connected at its inner end to the drive shaft and, at its outer end, to the vibrator, at least one of the universal connections for the power shaft Ibeing constructed and arranged in telescoping engagement with the power shaft to thereby to the frame means,

accommodate changes in shaft length due to vibrations.

5. The trench roller of claim 2 further characterized in that the trame means includes a main frame which carries the vibrator power means,

an auxiliary `frame spaced from the main frame which rotatably supports the compacting roller, and vibration isolating means which interconnects the main and auxiliary frames.

6. The trench roller of claim further characterized in that the vibration isolating means includes a plurality of elastomeric members which are secured to both the main and auxiliary frames,

said elastomeric members having the characteristics of exure and distortability of rubber.

7. The trench roller of claim 5 further characterized inthat the vibrator is formed as a cartridge assembly which is bodily insertable and removable into the compacting roller.

8. In combination in a trench roller,

frame means,

a compacting roller rotatably connected to the frame means,

a leveling wheel assembly connected to the frame means,

said leveling Wheel assembly including means for maintaining the height of the frame means with respect to a reference surface whereby said frame means will be level regardless of the difference in the height of the reference surface and a surface to be compacted by said compacting roller, and

means fastened to said frame means for connecting the frame means, and thereby the compacting roller, to means for moving the trench roller along the reference surface,

said trench roller thereby having only two rolling support points,

said connecting means including a connecting bar, one end portion of which is adapted for connection to a propelling vehicle,

the other end portion of which is connected to the yframe means,

that end portion connected to the frame means having structure for securing the connecting bar in any one of a plurality of positions with respect to the frame means for a given direction of movement, all of which cause the propelling force exerted on the frame means to pass substantially through the center of gravity.

9. The trench roller of claim 8 further characterized in that the structure for securing the connecting bar to the frame means including a pair of curved surfaces generally complementary to one another,

the curved surface on the connecting bar havin-g a slightly greater radius of curvature than the curved surface on the frame means whereby at least a two point contact will be made when the connecting bar is secured to the frame means by a fastener.

10. The trench roller of claim 8 further including means -for securing the connecting bar to opposite sides of the frame means to thereby enable the trench roller to be moved in opposite directions.

References Cited UNITED STATES PATENTS 2,197,395 4/ 1940 Keeler 94-50 2,240,236 4/ 1941 Aitken 94-50 X 2,639,652 5/1953 Wright 94-50 2,682,153 6/1954 Fink 94-50 X 2,685,777 8/1954 Plas 94-50 X 2,728,277 12/ 1955 McRae 94-50 3,146,686 9/ 1964 Grace 94-50 3,257,918 6/ 1966 Garis 94-50 NILE C. BYERS, J R., Primary Examiner. 

